Dental face bow assembly

ABSTRACT

A dental face bow adapted to be positioned around and aligned to the face of a patient; a mouth piece and fixed frame carrying three adjustable pivot joints for supporting the face bow; and positively driven positioning mechanisms for adjusting the pivot joints to provide a desired position and aspect of the face bow.

United States Patent [191 Arant Dec. 17, 1974 [54] DENTAL FACE BOW ASSEMBLY 3,052,030 9/1962 Spence 32/20 x 3,074,166 1/1963 Skallerup t. [76] Inventor Gene Alan, 2444 Juplter 3,423,834 l/l969 lrish 32/20 Huntsville, Ala. 90046 22 Filed; Jam 19, 1973 Primary Examiner-Louis G. Mancene Assistant ExaminerJ. Q. Lever [21] App]. No.: 324,957

[57] ABSTRACT [52] U.S. Cl. 32/19 A dental face bow adapted to be positioned around [51 Int. Cl. A61c 9/00 and aligned to the face of a patient; a mouth piece and [58] Field of Search 32/19, 20, 21 fixed frame carrying three adjustable pivot joints for supporting the face bow; and positively driven posi- [56] References Cited tioning mechanisms for adjusting the pivot joints to UNITED STATES PATENTS provide a desired position and aspect of the face bow.

2,418,648 4/1947 Kile 32/19 13 Claims, 22 Drawing Figures PATENIELJECI H974 I SHEET 1 OF 4 71/ AX/S DENTAL FACE BOW ASSEMBLY RELATED APPLICATION The present invention is an improvement over that disclosed in my prior copending application Ser. No. 259,452, filed June 5, 1972 and now abandoned.

BACKGROUND OF THE INVENTION In the indirect method of dentistry a dental articulator is used to simulate the chewing mechanism of a particular patient. It is necessary to position tooth casts or models in the articulator in their correct relative position. A transfer face bow is used to position the casts in the articulator. Such instruments heretofore in use have been limited in their precision and in their degree of adjustability.

In the indirect method of dentistry it is also necessary to measure dynamic movements of the jaws in order to provide an accurate simulation of the action of the temporomandibular joints. In recording dynamic jaw movements a recording instrument is used which includes both an upper face bow and a lower face bow. The preferred practice is that the upper recording face bow be precisely aligned to the head of the patient, and more specifically, with the extended hinge axis of the jaws.

The problem of supporting a transfer face bow in a fully adjustable position is essentially identical to the problem of supporting a recording face bow in a fully adjustable position. The present invention provides apparatus which may be used equally well for either purpose.

PRIOR ART Applicable prior art includes:

Face Bow: Hawksworth 1,703,105 Stuart 3 ,224,096 Lee 3 ,577,639

Pivot Joint: Wilt 1,117,123 Groves 1,608,276 Wharam 2,448,851 Pagliuso 2,670,228 Korecky 3,423,115

SUMMARY OF THE INVENTION According to the present invention the complete dental face bow assembly includes a fixed frame of rigid construction, a movable frame of rigid construction, and a set of three support means for supporting the movable frame from three corresponding points on the fixed frame. Each of the support means is individually adjustable, having at least 5 of freedom, so that the movable frame may be freely adjusted as needed. Each of the support means is also equipped with positively driven adjustment means.

More specifically, the fixed frame has a mouthpiece, left and right laterally extending arms, and a forward arm. One of the adjustable support means is associated with each of the arms of the fixed frame.

DRAWING SUMMARY FIG. 1 is an exploded perspective view of an adjustable mechanism which illustrates some of the mechanical principles of the present invention;

FIG.2 is an enlarged fragmentary cross-sectional view of one of the pivot joints of FIG. 1, taken along the longitudinal axis of the tubular member;

FIG. 3 is an enlarged fragmentary cross-sectional view of the same pivot joint but taken transverse to the tubular member;

FIG. 4 is a top plan view of the pivot joint of FIGS. 2 and 3;

FIG. 5 is a perspective view of a transfer face bow assembly in accordance with the present invention;

FIG. 6 is a side elevation view of the transfer face bow assembly of FIG. 5;

FIG. 7 is a front elevation view of the assembly of FIG. 5;

FIG. 8 is a fragmentary cross-sectional view taken on the line 88 of FIG. 7;

FIG. 9 is a cross-sectional elevational view taken on the line 9-9 of FIG. 6;

FIG. 10 is an exploded perspective view of a portion of one of the pivot joints together with its associated positive drive mechanisms and locking mechanisms;

FIG. 11 is an exploded perspective view of a recorder face bow assembly;

FIG. 12 is a cross-sectional elevational view taken on the line 1212 of FIG. 11;

FIG. 13 is an exploded perspective view of the frontal adjustment mechanism for the assembly of FIG. 11;

FIG. 14 is a fragmentary cross-sectional view in its assembled form of the frontal adjustment mechanism for the assembly of FIG. 11;

FIG. 15 illustrates a construction detail for the instrument of FIG. 11;

FIG. 16 is a side view of an alternate form of pivot oint;

FIG. 16a is a cross-sectional view of the pivot joint of FIG. 16;

FIG. 17 is an exploded perspective view of an alternate form of the mechanism of FIG. 10;

FIG. 18 shows an alternate form of elevation screw;

FIG. 19 illustrates a detail of the tubular frame;

FIG. 20 illustrates another form of pivot joint; and

FIG. 21 is a cross-sectional elevational view taken on the line 21-21 of FIG. 20.

THE ADJUSTABLE MECHANISM OF FIGS. 14, INCLUSIVE A rigid fixed frame FFl is formed from a single flat piece of material having a forward arm 10 and lateral arms 11 and 12, respectively. The lateral arms have a common axis 13 while the forward arm has an axis 14 which is perpendicular thereto. The arm ends are slotted on their respective axes to form respective slideways 16, 17, 18.

A rigid generally U-shaped movable frame MFl is formed from a single tubular member. In its upper wall it has elongated slots 30, 31, and 32 which are formed in the central portion and the two side portions, respectively. A round hole 34 is formed at the end of slot 30, and similar holes 35, 36 are formed at the ends of the slots 31, 32.

A set of three adjustable support means, or pivot joints 40, 41, 42 support the movable frame from the fixed frame. Each support means includes an elevation screw 44 and a slide plate 20, 21 or 22.

Each of the slide plates 20, 21, 22 is notched in a suitable manner so as to slide in the respective slideway of the fixed frame. The slide plates have respective threaded openings 24, 25, 26 each of which is aligned perpendicular to the plane of the fixed frame when the corresponding plate is seated in its associated slideway.

Each elevation screw 44 includes a threaded post 45 having a ball or sphere 46 attached to its lower end and a screwdriver notch 47 formed on its upper end. The threaded post is adapted to engage the threaded opening of a corresponding slide or base plate, and the ball or sphere 46 is of such diameter as to either rotate or slide longitudinally within the interior wall of the tubular frame MFl. The ball 46 is inserted through the corresponding opening 34, 35, or 36.

Reference is now made specifically to FIGS. 2-4, inclusive, illustrating the operation of pivot joint 40 which includes base plate 20. The width of slot 30 (FIG. 3) is considerably greater than the thickness of the lower end of post 45.

The pivot joint of FIG. 2-4, inclusive, has 6 of freedom, and hence may be adjusted in six different ways, as follows:

1. Elevation adjustment is made by using screwdriver slot 47 to turn threaded post 45'so as to raise or lower the ball 46 along the VE axis relative to base plate 20. a

2. The base plate 20 may be moved in the slideway 16 of frame arm to accomplish a transverse horizontal movement (relative to MFl) along the TH axis as indicated'in FIG. 4.

3. The tube may slide in longitudinal, horizontal movement along the Isl-I axis relative to the sphere 46.

4. The vertical angle VA of the tube, shown in FIG. 2, may be adjusted by lowering one end of the tube and raising the other end relative to the ball 46.

5. The tube may be twisted in a horizontal plane to vary its horizontal angle I-IA as shown in FIG. 4.

6. The tube may rotate about its own longitudinal axis relative to the elevation screw, as shown by curved arrow R in FIG. 3.

Although there are six adjustments for each of the three pivot joints, the positioning of movable frame MFl requires only a total of six positive adjustments to be made. These are preferably accomplished by adjusting the three elevation screws along the VE axis; adjusting the slide plate 20 along its TH axis (the axis 14); adjusting one of the slide plates 21, 22 along its TH axis (the axis 13) while permitting the other to slide freely as required; and rotating the movable frame relative to the fixed frame so that it moves along the LH axis relative to all three of the balls 46. It therefore follows that adjustment (1) of each pivot joint will always be positively controlled, adjustments (2) and (3) are sometimes positively controlled, and adjustments (4), (5) and (6) are always dependent or slave adjustments.

TRANSFER FACE BOW ASSEMBLY FIGURES 5-10, INCLUSIVE Reference is now made to FIGS. 5 to 10, inclusive, illustrating the transfer face bow assembly of the present invention.

Fixed frame FF2 has a centerpiece 113 and right and left lateral arms 111, 112 which are integrally formed from asingle flat piece of material. A bite plate or mouthpiece 118 is removably attached to center piece 113 by screws 1 19. Fixed frame F F2 also includes a for- I ward arm' 110 having its rearward end turned downwardly and welded to centerpiece 113 adjacent the left lateral arm 112. An orbital pointer 116having three degrees of adjustability is carried by a universal joint which in turn is attached to the right lateral arm 111 adjacent centerpiece 113.

Movable frame MF2 is a generally U-shaped frame made of a single tubular member which passes over the outer ends of the lateral arms 111, 112 of the fixed frame and underneath the outer end of the forward arm 110. Adjustable support means supports the center of movable frame MF2 beneath forward arm 1 10, while support means 141, 142 support the sides of the movable frame above the respective lateral arms. The ends of movable frame MF2 are fitted with axis alignment pins 131, 132 which slide on a common axis 133 representing the reference axis of MF2. Each of the axis alignment pins has an associated depth marker 135, 136 for measuring its length during an alignment condition.

The instrument is used first with the patient (FIG. 6) and later with an articulator (FIG. 5).

When used with the patient the bite plate 118 is grasped between the teeth and orbital pointer 116 is aligned to a tattoo mark on the nose. The adjustable support mechanisms 140, 141, 142 are adjusted so as to align the reference axis 133 of movable frame MF2 with the hinge axis of the patient. This is accomplished by placing the ends of both pointers 131, 132 on respective tattoo marks (not specifically shown) which represent the hinge axis of the patient. It is not absolutely essential that the ends of the movable frame MF2 be equal distances from the hinge axis tattoo marks, because the pin lengths are recorded by depth markers 135, 136.

When the instrument is aligned to an articulator the orbital pointer 116 engages an orbital plane indicatoreral separation of the hinge axis tattoo marks on the patients face. The depth markers are therefore utilized to set both axis pointers on an either longer or shorter depth than they had when aligned to the patient, and by equal amounts. In this manner an accurate static position transfer is achieved even though the frame MF2 may have been laterally asymmetrical, and even though the separation of the dimples 177 on the analog blocks is different from the separation of the tattoo marks on the patients face.

The adjustable support mechanism 141 shown in FIGS. 5, 6, 7, 9 and 10 will now be described.

Threaded post 145 engages vertical threaded opening 125 in the base plate 121. Ball or sphere 146 is attached to the upper end of post 145 and is also received within the interior of movable frame MF2. A jam nut 165 is threaded on the protruding lower end of the post 145. Screwdriver notch 147 is used for adjusting the elevation screw to its desired position of vertical adjustment, and then the jam nut 165 is turned in order to lock it in position. Thus the VE adjustment l) is positively controlled.

Base plate 121 slides in a slideway 117 formed in the outer end of the lateral arm 111. A tab 150 formed on an outer, upper corner of base plate 121 has a horizontal threaded opening 151 formed therein. A tab 155 with horizontal smooth opening 156 is attached to the lateral arm 111 adjacent the inner end of slideway 117.

A lead screw 160 is horizontally disposed, parallel to slideway 117, and has on its inner end a smooth groove 161 which is locked in opening 156 of tab 155. The outer threaded end of lead screw 160 engages the threaded opening 151 on base plate 121. A screwdriver notch 162 on the outer end of the lead screw is used to adjust the base plate either inwardly or outwardly relative to the lateral arm 111. A set screw 153 carried on the underside of base plate 121 is used to lock it in its selected position of adjustment. Thus the TH adjustment (2) on the common lateral axis of the slideways of arms 111, 112 is positively controlled.

The adjustable support mechanism 142 is constructed in the same manner except that lead screw 160, tabs 150 and 155, and set screw 153 may be omitted since the TH adjustment of slide plate 122 moves in a slave relationship to the slide plate 121.

Adjustable mechanism 140 is constructed the same as the mechanism 141 but is inverted because movable frame MP2 passes underneath the forward arm 110. Also, provision is made here to lock the LH adjustment (3) of the movable frame. This is accomplished by a staple 167 (FIGS. 5 and 8) driven through the tube to lock ball 146 against longitudinal sliding movement. Movable frame MF2 therefore has only five degrees of adjustability.

Alternatively, it may be preferred to dispense with depth markers 135, 136 as well as the locking means 167. The LH adjustment may then be positively controlled by a drive mechanism similar to that shown in FIGS. 13 and 14. The block 210 and associated portion of plate 200 would be omitted, however.

RECORDER FACE BOW ASSEMBLY FIGURES 1 1-15 Reference is made to FIGS. 11-15, inclusive, illustrating a recorder face bow assembly in accordance with the present invention.

Fixed frame FF3 is identical to fixed frame FFl shown in FIG. 1, and movable frame MF3 is identical to movable frame MFl. Relative positions are reversed, however, with the movable frame being supported above the fixed frame. The adjustable support means 241 may be identical to the adjustable supportmeans 141 shown in FIG. 10. Adjustable support means 242, not specifically illustrated in FIG. 11, may be identical to support means 142.

Adjustable support means 240 is somewhat different from those previously described, and is illustrated in FIGS. 11, 13 and 14. It includes a slide 220 identical to the slides 120 and 121 as previously described; an elevation screw 244 identical to elevation screw 144 as previously described; and other mechanism associated therewith as previously described in conjunction with FIG. 10. In addition, it includes means for positively controlling the LH adjustment (3).

More specifically, a slide member 250 has fingers 251, 252 which extend into the slot of movable frame MF3 and grasp the ball 246 on respective sides thereof. Slide member 250 also has a tab portion projecting perpendicular to MF3 in which a threaded horizontal opening 253 is formed. A lead screw 260 is received in the opening 253. A support plate 200 is attached to the upper surface of MF3 and extends forwardly thereof.

Support plate 200 has a pair of downwardly depending ears 266, 268 in which openings 267, 269 are formed. Lead screw 260 has smooth grooves 261, 262 formed adjacent its respective ends, and which are-snapped into the openings 267, 269, respectively. The lead screw may then be driven from either of the screwdriver slots 263, 264 at its two ends. By rotating the lead screw 260 the movable frame MF3 is caused to rotate on its tripod base of support, so that all three of the balls slide longitudinally within the tubular frame.

The instrument of FIG. 11 also includes a pairof lateral support plates 201, 202 which are vertically disposed and attached to the outer surface of the frame MF3 near its respective extremities. FIG. 15 shows attachment of the plate 201 by welding at the points 201a, 201b.

A pair of alignment blocks 206, 207 are removably attached in aligned positions to the support plates 201, 202, respectively. Each alignment block has a horizontal opening therein and the axes of the two openings are collinear. A pair of axis alignment pins 231, 232 are disposed in respective ones of the alignment blocks, and their points lie on the common axis 233 representing the reference axis of the movable frame MF3.

Just to the right of support plate 200 a vertical bolt 215 extends through a vertical opening in the movable frame MF3 and supports an orbital pointer 216. A nut 215a on bolt 215 may be loosened to adjust either the length or angular position of pointer 216. Pointer 216 and axis 233 lie in a common plane.

The instrument is applied to dentistry in a manner generally described by R. L. Lee, DDS in the Aug, 1969 issue of The Journal of Prosthetic Dentistry. Upper clutch 218 is attached to the upper tooth structure of the patient and fixed frame FF3 is attached rigidly to the clutch. Then the various support mechanisms are positively adjusted in order to align the axis pins 231, 232 with the tattoo marks on the patients face representing the terminal hinge axis location. At the same time movable frame MF3 is laterally positioned so that the pointers 231, 232 project inwardly from their respective alignment blocks by equal distances. Pointer 216 is also aligned to the nose tattoo mark. The recording position of frame MF3 has then been established. All of the adjustable positioning mechanisms are then locked in place utilizing the three jam nuts 165, the two set screws 153, and any appropriate means for securing the slide 250 and lead screw 260. Then the pointers 231, 232 are removed. A lower recording face how, not shown in the present drawings, is aligned in its proper position by utilizing the axis alignment blocks 206, 207. Thereafter, the axis alignment blocks 206, 207 are removed and are replaced with locigraph blocks, not shown. A third locigraph block 210 is attached to the under surface of support plate 200. The dynamic jaw movement pattern of the patient is then recorded by cutting grooves in the three locigraph blocks.

ALTERNATE CONSTRUCTION DETAILS FIGURES 16-21 FIGS. 16 and 16a show an alternate pivot joint construction. An elevation screw includes threaded post 245 having ball 246 attached to one end. The other end of the post engages a threaded opening in slide plate 321. Movable frame MF4 carries a sliding sleeve 322 which on its upper side has a socket 323 for the ball. The VE, TH, LH, VA, HA, and R movements are indicated by appropriate arrows.

While frame MF4 is shown as being of rectangular cross-section, it may if desired be cylindrical, and sleeve 322 is then made of circular configuration.

FIG. 17 illustrates an alternate slide construction. The lateral arm 111a of the fixed frame is relatively thick and has a slideway 117a formed therein with overhanging edges on its two side walls. The base plate 121a of an elongated octagon configuration is adapted to be slidingly received in the slideway 117a. The slide 121a has gear teeth 121b formed on one of its longitudinal edges. A gear wheel 160a is received in a vertical opening in one side of the arm 111a, its upper end being retained by a cap 155a. The lower end of the gear wheel has a screwdriver slot 162a which is used to rotate the gear wheel and hence drive the slide 121a either inward or outward. A set screw 153a is used to lock the gear wheel 160a against further rotation, when slide 121a has been positioned. Slide 121a also has a threaded vertical opening 125a for receiving an elevation screw, not specifically shown.

Reference is made to FIG. 18 showing an alternate form of elevation adjustment screw 144a. The threaded post 145b has a relatively small neck 145a, inserted into an opening in the ball 146 and fastened therein. The diameter of neck 145a is significantly less than the diameter of ball 146. The post 145b, however, has a diameter which is greater than the diameter of the ball 146.

FIG. 19 shows that a hole 170 in movable frame MFS may be braced by means of an internal plug 172 which is welded to the hole edge, or alternatively an outside patch 173 may be used to cover hole 171.

Reference is now made to FIGS. and 21 illustrating still another pivot joint construction. A frame member MP6 consists of a flat strip of material having a rectangular cross-sectional configuration. A short tubular member 185 has its two ends cut off to form angled surfaces 186, 187, so that when seen from the side as in FIG. 21 the member 185 has a trapezoidal configuration. A slot 188 is out throughout the length of the short side of the side wall of the tubular member 185. The opposite side wall is flattened somewhat at 189 and bears against the laterally central portion of the frame member MF6. The respective ends of tubular member 185 are riveted to frame member MF6 by means of rivets 191), 191. Threaded post 145 has one end attached to the ball 146, and it will be noted as shown in FIG. 21) that the slot 188 is significantly wider than the width of the post 145. During assembly, the ball 146 is inserted into the tubular member 185 before the second rivet is in place. The rivets then serve to captivate the ball 146 so that it cannot escape. The sloping ends of the tubular member provide convenient clearance for installation of the rivets. The length of tubular member 185 is selected as necessary to provide the longitudinal adjustment capacity for the pivot joint.

While the present invention has been described specifically in at least one of its forms, such detailed disclosure has been made only in order to comply with the patent laws and is not intended in any way to limit the concept or scope of the invention, which is more particularly defined in the accompanying claims.

I claim:

1. A dental face bow assembly comprising:

a rigid fixed frame adapted to be supported from a mouthpiece held in the mouth of a patient, said fixed frame having left and right lateral arms and aforward arm;

a unitary, rigid generally U-shaped movable frame adapted to extend around the face of the patient, having means on its ends for aligning both of its ends, concurrently, with the hinge axis of the patients jaws as represented by a pair of reference points on the patients face;

an orbital pointer carried by one of said frames and adapted to be aligned to a third reference point on the patients face;

three individually adjustable support means associated with corresponding ones of said arms for supporting said movable frame at three corresponding support locations whereby said movable frame may be supported in a desired alignment position relative to said three reference points; and

each of said support means including an elevation screw that is manually operable for controlling the elevation of said movable frame at the associated support location.

2. The assembly of claim 1 wherein at least one of said elevation screws has a sphere attached to one end thereof; and which further includes means coupling said sphere to said movable frame for 3 of twisting movement relative thereto, and also for longitudinal sliding movement of said movable frame relative to said sphere.

3. The assembly of claim 2 wherein said movable frame is of tubular configuration and has an elongated slot formed in its side wall, said sphere being received within said tubular frame in rotating and sliding engagement therewith, said elevation screw end extending through said slot, and the width of said slot being greater than the width of said screw end.

4. The assembly of claim 1 wherein one of said fixe frame arms has a slideway extending transversely to said movable frame at the associated support location, and which further includes a slide plate movable in said slideway, said slide plate having a threaded opening which receives the corresponding one of said elevation screws.

5. A dental face bow assembly comprising:

a rigid fixed frame, including left and right lateral arms and a forward arm, adapted to be supported from a mouth piece held in the mouth of a patient;

a unitary, rigid generally U-shaped movable frame adapted to extend around the face of the patient;

three separate adjustable support means, one associated with each of said arms, supporting said movable frame from said fixed frame; and

separate control means manually operable for positively controlling each of said adjustable support means so as to achieve a desired alignment of said movable frame relative to the face of the patient;

each of said lateral support means having six degrees of adjustability and the forward support means having at least five degrees of adjustability.

6. A dental face bow assembly comprising:

a rigid fixed frame adapted to be supported from a mouth piece held in the mouth of a patient;

an integrally formed, rigid generally U-shaped movable frame adapted to extend around the face of the patient, at least a portion of the length of said movable frame being of tubular construction;

an elevation screw having one end threadedly coupled to said fixed frame, said tubular portion of said movable frame having an elongated slot formed in the side wall thereof, said elevation screw extending through said slot and the width of said slot being greater than the width of said screw;

a sphere attached to the other end of said elevation screw, said sphere being received within said tubular frame in rotating and sliding engagement therewith; and

said elevation screw being manually rotatable for adjusting the elevation of said movable frame relative to said fixed frame whereby said screw and sphere together provide five degrees of adjustability of the position of said movable frame relative to said fixed frame.

7. A dental face bow assembly comprising:

a rigid generally U-shaped movable frame having a tubular configuration at its center and its lateral side portions, each of said tubular portions having a longitudinal slot in the exterior wall thereof;

three spheres received within respective ones of said tubular portions in rotating and sliding engagement with the interior wall surfaces thereof;

three posts attached to respective ones of said spheres, each post extending outward through the associated slot and having a thickness which is less than the slot width whereby said post and its associated sphere may rotate in a plane perpendicular to 10. The face bow assembly of claim 9 wherein said adjustable means also includes means for adjusting the position of each of said posts in a substantially radial direction relative to the common center of said posts.

11. The face bow assembly of claim 9 which further includes separate means for positively driving the length adjustment of each of said posts.

12. The face bow assembly of claim 10 which further includes separate means for positively driving the length adjustment of each of said posts, and separate means for positively driving each of two of the radial adjustments of said posts.

13. The face bow assembly of claim 12 which further includes positively driven means for adjusting the rotational position of said movable frame in its own plane relative to one of said spheres. 

1. A dental face bow assembly comprising: a rigid fixed frame adapted to be supported from a mouthpiece held in the mouth of a patient, said fixed frame having left and right lateral arms and a forward arm; a unitary, rigid generally U-shaped movable frame adapted to extend around the face of the patient, having means on its ends for aligning both of its ends, concurrently, with the hinge axis of the patient''s jaws as represented by a pair of reference points on the patient''s face; an orbital pointer carried by one of said frames and adapted to be aligned to a third reference point on the patient''s face; three individually adjustable support means associated with corresponding ones of said arms for supporting said movable frame at three corresponding support locations whereby said movable frame may be supported in a desired alignment position relative to said three reference points; and each of said support means including an elevation screw that is manually operable for controlling the elevation of said movable frame at the associated support location.
 2. The assembly of claim 1 wherein at least one of said elevation screws has a sphere attached to one end thereof; and which further includes means coupling said sphere to said movable frame for 3* of twisting movement relative thereto, and also for longitudinal sliding movement of said movable frame relative to said sphere.
 3. The assembly of claim 2 wherein said movable frame is of tubular configuration and has an elongated slot formed in its side wall, said sphere being received within said tubular frame in rotating and sliding engagement therewith, said elevation screw end extending through said slot, and the width of said slot being greater than the width of said screw end.
 4. The assembly of claim 1 wherein one of said fixed frame arms has a slideway extending transversely to said movable frame at the associated support location, and which further includes a slide plate movable in said slideway, said slide plate having a threaded opening which receives the corresponding one of said elevation screws.
 5. A dental face bow assembly comprising: a rigid fixed frame, including left and right lateral arms and a forward arm, adapted to be supported from a mouth piece held in the mouth of a patient; a unitary, rigid generally U-shaped movable frame adapted to extend around the face of the patient; three separate adjustable support means, one associated with each of said arms, supporting said movable frame from said fixed frame; and separate control means manually operable for positively controlling each of said adjustable support means so as to achieve a desired alignment of said movable frame relative to the face of the patient; each of said lateral support means having six degrees of adjustability and the forward support means having at least five degrees of adjustability.
 6. A dental face bow assembly comprising: a rigid fixed frame adapted to be supported from a mouth piece held in the mouth of a patient; an integrally formed, rigid generally U-shaped movable frame adapted to extend around the face of the patient, at least a portion of the length of said movable frame being of tubular construction; an elevation screw having one end threadedly coupled to said fixed frame, said tubular portion of said movable frame having an elongated slot formed in the side wall thereof, said elevation screw extending through said slot and the width of said slot being greater than the width of said screw; a sphere attached to the other end of said elevation screw, said sphere being received within said tubular frame in rotating and sliding engagement therewith; and said elevation screw being manually rotatable for adjusting the elevation of said movable frame relative to said fixed frame whereby said screw and sphere together provide five degrees of adjustability of the position of said movable frame relative to said fixed frame.
 7. A dental face bow assembly comprising: a rigid generally U-shaped movable frame having a tubular configuration at its center and its lateral side portions, each of said tubular portions having a longitudinal slot in the exterior wall thereof; three spheres received within respective ones of said tubular portions in rotating and sliding engagement with the interior wall surfaces thereof; three posts atTached to respective ones of said spheres, each post extending outward through the associated slot and having a thickness which is less than the slot width whereby said post and its associated sphere may rotate in a plane perpendicular to the longitudinal center line of that portion of said movable frame; a fixed frame; and support means adjustably coupling said three posts to said fixed frame so that said two frames may move in three dimensions relative to each other.
 8. The face bow assembly of claim 7 wherein said movable frame is integrally formed from a single tubular member.
 9. The face bow assembly of claim 7 wherein said posts are substantially parallel to each other, and said adjustable means includes means for adjusting the length of each of said posts relative to said fixed frame.
 10. The face bow assembly of claim 9 wherein said adjustable means also includes means for adjusting the position of each of said posts in a substantially radial direction relative to the common center of said posts.
 11. The face bow assembly of claim 9 which further includes separate means for positively driving the length adjustment of each of said posts.
 12. The face bow assembly of claim 10 which further includes separate means for positively driving the length adjustment of each of said posts, and separate means for positively driving each of two of the radial adjustments of said posts.
 13. The face bow assembly of claim 12 which further includes positively driven means for adjusting the rotational position of said movable frame in its own plane relative to one of said spheres. 